Feeding mechanism for rock drills



March 7, 1939. Af FEUCHT FEEDING MECHANISM FOR ROCK DRILLS 2 sheets-sheet 1 Filed Sept. 28, 1957 w ww uw,

ALBERT F'Y/C/T INVENTOR ATTORNEY A. FEUCHT March 7,'1939.

FEEDING MECHANISM FOK ROCK-DRILLS Filed Sept. 28, 1937 2V Sheets-Sheet' 2 Abi/S97 FZ7/CHT INVENTOR l ATTORNEY Patented Mar. 7, 1939 2,149,592 FE-EDING MECHANISM FOR ROCK DRILLS Albert Feucht, Garfield Heights, Ohio, assigner to The Cleveland Rock Drill Company,

Cleveland, Ohio, a corporation of Ohio Application September 28, 1937, Serial No. 166,153

6 Claims.

This invention relates broadly to rock drills, but more particularly to a power actuated feeding mechanism for rock drills of the drifter type.

In rock drills of the drifter type, there is incorporated a rotation mechanism for imparting rotation to the drill steel during drilling operation. This mechanism is well known in this art, it comprises a rifle bar operatively associated with the reciprocatory hammer piston. Carried by this rifle bar, there are pawls engageable with the teeth of a stationary ring. During one stroke of the piston, the pawls prevent the rotation of the bar, thus resulting in the rotation of the hammer which is transmitted to the drill steel. During the other stroke of the piston, the rifle bar is free to rotate While the piston moves axially without rotation, thus resulting in an intermittent rotary motion of the rifle bar in one direction during the normal reciprocatory motion of the piston.

It is an object of this invention to utilize the rotary motion imparted to the rifle bar of a drilling motor for feeding the motor toward or away from the work.

Another object of this invention is to produce adequate means for transmitting rotation from a rock drill rotation mechanism to a feeding mechanism for actuating the latter without affecting the operation of the former.

Another object of this invention is to produce a rock drill feeding mechanism forming a compact and light assembly which is strong, durable and comparatively inexpensive to manufacture.

Other'objects and advantages more or less ancillary to the foregoing reside in the specic construction and aggroupment of the elements peculiar to this structure, as will become apparent from a more complete examination of this specification.

In the drawings:

Fig. 1 is a side elevational View of a rock drill embodying the invention.

Fig. 2 is an enlarged cross sectional View taken through a plane indicated by line 2-2 in Figs. 1 and 6.

Fig. 3 is a longitudinal sectional view taken through a plane indicated by line 3-3 in Fig. 2.

Fig, 4 is an enlarged cross sectional View taken through a plane indicated by line 4-4 in Fig. 3.

Fig. 5 is an enlarged cross sectional view taken through a plane indicated by line 5-5 in Fig. 3.

Fig. 6 is a diagrammatical view of the gears incorporated in the mechanism.

Referring to the drawings in which like symbols designate corresponding parts throughout the several views, lll represents a fluid actuated rock drill including a cylinder Il having reciprocable therein a piston (not shown) delivering impacts to a drill steel I2 slidably mounted within a front housing i3. VThis rock drill or drilling motor l@ is slidably guided on a support or shell i4, which accommodates a feed screw l5 extending lcngitudinally thereof well beyond the left end of the shell where it is supported by a cross head lll and side bolts Il, which bolts are cutaway in Fig. 1 to show details of construction, The screw l5, which is of the usual self locking type, is locked against rotation by a nut I8, and extends through two axially disposed bosses I9 and 2l), the former depending from a housing 2l which is secured to the cylinder l l by side bolts 22, while the latter depends from the cylinder ll. Mounted within the boss i9 against axial movement, there is a rotatable nut 23 in operative engagement with the stationary screw l5, while the boss 20 is formed with a smooth bore of a diameter substantially larger than that of the screw.

Accommodated within the rear end of the cylinder Il, there is the rotation mechanism actuated by virtue of the reciprocation of the hammer piston for imparting intermittent rotary motion in one direction to the drill steel l2. This mechanism is of the type usually encountered in rock drills, and since it is well known in this art, a specific description of the same is not thought necessary other than pointing out that the mechanism includes a rifle bar 24 extending into the cylinder where it engages the reciprocable piston. This rifle bar is formed with a head 25 carrying pawls engageable with a ratchet ring 2t for controlling the rotation of the bar. Beyond the head 25, the bar has a stem extension 2l journaled within a bearing plate 28.

Mounted within the housing 2| coaxially with the rifle bar 2li, there are two shafts 29 and 30, the shaft 30 being connected to the rifle bar stem 2l against rotation relative thereto by a suitable connection 3i. Extending over the abutting ends of the shafts 29 and 30, there is a connecting sleeve 32 having one end portion formed with a counterbore 33 within which are mounted two diametrically opposed shoes or friction members t@ which are carried by the adjacent end portion of the shaft 30. Extending radially from the inner wall of each shoe 34, there is an integral tit 35 fitted closely within a corresponding flat bottom bore 36 provided within the shaft 35 for preventing rotation of the shaft relative to the shoes. The tit 35 is hollow CII and has disposed therein a compression spring 31 interposed between the shaft on the shoe for effecting the frictional engagement of the latter with the inner wall of the counterbore 33.

Between the sleeve 32 and the shaft 29, there is a resilient driving connection including a spiral spring 38 having its outer end pivotally secured to the sleeve by a pin 39, While its inner end is pivotally connected to the shaft 29 by a pin 40. Formed on the shaft 29, there are two gears 4l and 42, the gear 4| meshing with an idler gear 43 rotatably mounted on a shaft 44. Below the shaft 29, the housing 2| accommodates another shaft 45 having a gear 46 slidable thereon in operative engagement with either the gear 42 or the idler gear 43. The gear 46 is also in operative slidable engagement with gear teeth 41 formed on the nut 23, and is provided with an annular groove 48 adapted to receive the tip 4S of a rotatable handle 58 having a body portion 5| rotatable within the housing 2| and detachably secured therein by a nut 52. The tip 48 is formed eccentrically relative to the center axis of the body portion 5l, and is locked against accidental rotation by a spring pressed plunger 53 engaging detents 54 formed on the body portion 5|.

Rotatably mounted within the housing 2|, there is the usual throttle valve 55 having motive fluid admitted therein, and from which it may ilo-w into the drilling motor for actuating the same through a radial port 56, an annular groove 51 formed within the plate 28, and a port 58 located within the cylinder In the operation 4of the mechanism, let it be .j assumed that motive iluid from the throttle valve 55 is admitted into the drilling motor Il) for effecting the reciprocation of the hammer piston therein in the usual way, thereby causing the intermittent rotation in one direction of the i rifle bar 24 in the manner well known in this art. In the present mechanism, the rotation of the bar 25 is transmitted to the shaft 30 through the connection 3|, and from the shaft 30 normally to the sleeve 32 through the friction clutch including the shoes 34 in frictional engagement with the inner wall of the sleeve counterbore 33. From the sleeve 32, the rotation is finally transmitted to the shaft 29 through the resilient connection including the spiral spring 38.

In machines of this type, the rifles or helical splines of the rie bar 24 are usually machined in a direction causing the rotation of the bar in a counterclockwise direction when viewed from the left end of the machine in Fig. 1, which rotation is transmitted to the shaft 29 as above described in a counterclockwise direction in Fig. 2. With the gear 46 positioned as shown in Fig. 3, the rotation of the shaft 30 in a counterclockwise direction is transmitted to the nut 23 in the same direction due to the operative engagement of the gear 46 with the gear 42 and with the gear teeth 41 of the nut 23, thereby causing the forward feeding movement of the drilling motor I9 due to the operative engagement of the nut with the stationary screw I5.

When it is desired to feed the drilling motor in the other direction, the handle 50 may be rotated about 90, thus causing the slidable movement of the gear 46 out of operative engagement with the gear 42 and in operative engagement with the idler gear 43,V which is in operative engagement with the gear 4| carried by the shaft 29. In this instance, rotation in a counterclockwise direction is imparted to the gear 46, and therefrom to the nut 23 in a clockwise direction eifecting the rearward feeding movement of the drilling motor.

When the feeding mechanism is operating under normal condition, the tension of the spiral spring 38 is calculated to resist substantial winding of the spring, causing rotation from the sleeve 32 to be transmitted to the shaft 29 at substantially the same rate of speed. However, should the mechanism be operating under unusual or adverse condition preventing the drilling motor to be fed at its normal rate of speed, the rifle bar 24 would, if rigidly connected to the shaft 29, be prevented to rotate at its regular speed, and would thereby seriously interfere with the free reciprocation of the hammer piston within the cylinder In the present construction, when the drilling motor is operated under such adverse condition, the sleeve 32 still driven by the rifle bar 24 will cause the winding of the spring 38 while the shaft 29 either remains stationary or rotates at a slower rate of speed than that of the sleeve 32, thereby enabling the operation of the drilling motor even though its feeding motion is entirely or partially prevented. The tension of the spring 38 as well as the friction of the shoes 34 on the sleeve 32, are calculated to cause the slipping of the friction clutch immediately prior to the complete winding of the spring, thereby still allowing the rotation of the rifle bar 24 and the normal actuation of the drilling motor even though the feeding motion of the motor is prevented for any length of time.

When the drilling motor is again free to be fed toward or away from the work, the friction shoes 34 will automatically engage the sleeve 3:2 for transmitting rotation thereto which will be transmitted therefrom to the shaft- 29 through the spring 38. In this instance, the rate of feeding speed imparted to the drilling motor will be somewhat above normal due to the rotative energy stored within the spring 33, which energy is transmitted to the nut 23 in addition to the rotative energy directly transmitted thereto from the rifle bar 24. In other words, while the rifle bar normally effects an intermittent rotation of the nut 23, the spring 38 due to the rotative energy stored therein, will effect a constant rotation of the nut resulting in a constant feeding motion of the drilling motor until the energy stored within the spring is entirely dissipated.

From the foregoing description, it will be understood that in the present construction the feeding mechanism is actuated by the rotation mechanism incorporated in the motor and actuated by the reciprocation of the hammer piston. It will also be understood that due to the resilient connection including the spiral spring 38, feeding motion may be imparted to the drilling motor at a different rate of speed, either slower or faster, than the normal speed resulting from the rotation of the rifle bar 24, and that due to the friction clutch between the shaft 30 and the sleeve 32, the rifle bar 24 is capable of rotation without imparting feeding motion to the drilling motor.

Although the foregoing description is necessarily of a detailed character, in order to completely set forth the invention, it is to be understood that the specific terminology is not intended to be restrictive or -conning and it is to be further understood that various rearrangements of parts and modications of structural detail may be resorted to without departing from the Vscope or, spirit of the invention as herein claimed.

I claim:

1. In a drilling apparatus, the combination with a support, of a drilling motor slidable on the support having a uid actuated piston reciprocable therein, of a rotation mechanism included in said motor automatically actuated due to the reciprocatory motion of said piston, of a feeding mechanism for said motor including a stationary screw carried by the support in operative engagement with a rotatable nut carried by the motor for effecting feeding motion of the motor upon rotation of said nut, `and resilient means for transmitting rotation from said rotation mechanism tosaid nut. I

2. In a drilling apparatus, the combination with a support, of a drilling motor slidable on the support having a fluid actuated piston reciprocable therein, of a rotation mechanism included in said motor automatically actuated due to the reciprocatory motion of said piston, of a feeding mecha- .nism for said motor including a stationary screw carried by the support in operative engagement with a rotatable nut carried by the motor for eiecting feeding motion of the motor upon rotation of said nut, and rotation transmitting means between said rotation mechanism and nut including means capable of accumulating rotative energy upon a predetermined resistance to rotation of said nut and capable of release for imparting additional rotative power to said nut.

3. In a drilling apparatus, the combination with a support, of a drilling motor slidable on the support having a uid actuated piston reciprocable therein, of a rotation mechanism included in said motor automatically actuated due to the reciprocatory motion of said piston, of a feeding mechanism for said motor including a duality of elements in operative engagement with each other one rotatable relative to the other for effecting feeding motion of the motor, and rotation transmitting means between saidlrotation mechanism and the rotatable element including rotative energy accumulating means capable of release for imparting additional rotative power to said rotatable element.

4. In a drilling apparatus, the combination with a support, of a drilling motor slidable on the support having a rotatable drill steel carried thereby, of a power actuated rotation mechanism for said drill steel, of a feeding mechanism for said motor including a duality of elements in operative engagement with each other one rotatable relative to the other for effecting feeding motion of the motor, means for resiliently transmitting rotation from said rotation mechanism to the rotatable element, and clutch means for automatically preventing said transmission when said rotatable element is subjected to a predetermined resistance to rotation. Y

5. In a drilling apparatus, the combination with a support, of a drilling motor slidable on the support having a rotatable drill steel carried thereby, of a power actuated rotation mechanism for said drill steel, of a feeding mechanism for said motor including a duality of elements in operative engagement with each other one rotatable relative to the other for eecting feeding motion of the motor, means including a resilient member capable of limited deflection for transmitting rotation from said rotation mechanism to the rotatable element, and clutch means automatically preventing said transmission when said member reaches its maximum deflection.

6. In a drilling apparatus, the combination with a support, of a drilling motor slidable on the support having a fluid actuated piston reciprocable therein, of a rotation mechanism included in said motor automatically actuated due to the reciprocatory motion of said piston, of a feeding mechanism for said motor including a duality of elements in threaded operative engagement with each other one carried by the support and the other by the motor, one of said elements being rotatable relative to the other for eiecting feeding motion of the motor, means including a resilient connection capable of limited deflection for transmitting rotation from said rotation mechanism to the rotatable element, and clutch means arranged for automatically preventing said transmission when said connection reaches its maximum deection.

ALBERT FEUCHT.

DISCLAIMER 2,149,592.-Alberi Feucht, Garfield Heights, Ohio. FEEDING MEcHANIsM FOR Rocx DRILLS. Patent dated March 7, 1939. Disclaimer filed March 9, 1940, by the assignee, The Cleveland Rock Drill Company. Hereb y enters this disclaimer to claims 1 and 4 in said specification.

[Oficial Gazette April 2, 1.940.] 

